1. Field of the Invention
The present invention relates to a seat tube of a bicycle, and more particularly to a seat tube having a device for adjusting a height of a saddle of a bicycle.
2. Description of Related Art
A seat post is connected between a seat tube and a saddle, so a height of the saddle can be adjusted by sliding the seat post relative to the seat tube.
In order to hold the seat post in position relative to the seat tube, the seat tube has a top end, two fastening rings and a slit. The fastening rings protrude from the top end of the seat tube. The slit is defined in the top end of the seat tube between the fastening rings. When fasteners are tightened against the fastening rings, the slit is narrowed to hold the seat post in position.
However, with the fastening rings and the fasteners protruding from the seat post, users are easily injured by the fastening rings and fasteners.
To overcome the shortcomings, the present invention tends to provide a seat tube of a bicycle to mitigate or obviate the aforementioned problems.